Consumable industrial propellant cartridge

ABSTRACT

A consumable industrial propellant cartridge having a formstabilized annular propellant charge body filled with loose ignitor composition and closed at both ends with a relatively thin powder foil coated on its inside surface with a percussionsensitive material, for example, tetrazene or tetrazenetrizinate.

United States Patent [72] Inventors Heinz Gawlick Furth; GuntherMamndel, Erlangen, Germany [21] Appl. No. 668,797 [22] Filed Sept. 19,1967 [45] Patented May 25, 1971 [73] Assignee Dynamit NobelAktiengesellschaft Troisdorf, Germany [54] CONSUMABLE INDUSTRIALPROPELLANT CARTRIDGE 7 Claims, 2 Drawing Figs. [52] US. Cl 102/101,102/39, 102/45, 102/86.5, 102/40 [51] Int. Cl F42b l/02 [50] FieldofSearch 102/38, 39, 99, 100, 101, 104, 45, 86.5; l49/10,2,14, 15,16

[56] References Cited UNITED STATES PATENTS 53,168 3/1866 Moffatt 102/45694,295 Maxim 102/100 726,901 5/1903 Gathmann". 102/101 1,316,360 9/1919Delpech 149/14 2,407,264 lO/l946 Ferrel lO2/86.5

3,311,057 3/1967 Quinlan et al. 102/38 3,372,643 3/1968 Kvavle 102/99OTHER REFERENCES Bebie, Manual of Explosives, Military Pyrotechnics andChemical Warfare Agents, Compositions Properties Uses, 1943, page 144Primary Examiner-Robert F. Stahl Att0meyCraig, Antonclli, Stewart & HillABSTRACT: A consumable industrial propellant cartridge having aform-stabilized annular propellant charge body filled with loose ignitorcomposition and closed at both ends with a relatively thin powder foilcoated on its inside surface with a percussion-sensitive material, forexample, tetrazene or tetrazenc-trizinate.

PATENTEU MAYZSISYI 3580.180

Es mvmrons I I HEINZ GAWLICK GUNTHER' MARONDEL BY 6% d @wza- ATTOR NEY.

CONSUMABLE INDUSTRIAL PROPELLANT CARTRIDGE BACKGROUND OF THE INVENTIONIt is particularly desirable to obtain a propellant cartridge that willnot produce impurities that would impair the rapid recharging andoperation of an industrial powder-chargedriven apparatus, particularlyfor driving bolts, stunning cattle, etc. Cartridges known prior to thepresent invention satisfy this requirement only to an inadequate degree,or not at all, because the high pressure prevailing in the cartridgechamber will commonly splinter or tear the walls of the cartridge casethus producing residues that remain within the cartridge chamber of theindustrial apparatus. While attempts have been made to obviate thisdrawback, for example by providing predetermined breaking zones in thecartridge case, none of these attempts have met with decisive success.

It has generallybeen thought to be impossible to eliminate the cartridgecase, because of safety requirements.

SUMMARY OF THE INVENTION It is an object of the present invention toovercome the above disadvantages by providing an industrial propellantcartridge that is completely consumable within the cartridge chamberwithout leaving any residues. Also, the unnecessary weight of thecartridge case is economically and advantageously eliminated. Thecartridge of the present invention employs a cast or pressed propellantpowder body having preferably a centrally located recess filled with apowder charge that is easily ignitable by percussion.

The danger of unintentional ignition outside of the cartridge case isnot present with the cartridge of the present invention, because thecartridge itself does not have an anvil required for ignition, or ifsuch an anvil is used, the ignition will be brought about only by animpact or percussion upon the percussionsensitive powder charge disposedwithin the recess of the powder charge body, which would require aspecific detonating tool that could be inserted into the recess.

The main powder charge body may be provided as a flat tablet with acentral depression or recess extending over substantially the entireheight thereof. Such a construction is particularly advantageous inregard to casting or pouring the powder body. Also, the propellantpowder body may be provided as a flat ring or annular element, which isalso well suited for casting.

The propellant powder charge with the central recess eliminates the needfor orienting the propellant cartridge within the cartridge chamber ofthe firing apparatus, since the cartridge may be struck by thedetonating element from either axial end. It is particularlyadvantageous to cover the recess or central depression with a powderfoil, which may be secured by bonding or gluing. If the powder body isin the form of a ring, a powder foil may be provided to cover both endsof the central aperture.

With the employment of powder foils for covering the cen tral recess oraperture, it is particularly desirable to construct the powder foil froma percussion-sensitive powder, that is a powder that is readilyignitable by percussion or impact. Also, the ignition or detonatingsafety and the intensity of the propellant charge kindling orinflammation may simultaneously be advantageously increased by providinga foil for covering the central recess or aperture and coating theinside surface of the foil with a mixture readily ignitable bypercussion, for example tetrazene or tetrazene-trizinate. When a centralrecess or aperture is completely covered by one or more foils, thepercussion-sensitive powder within the recess or aperture may be loosegrained to increase its ignition sen sitivity. The powder foil may bethe only element ignitable by percussion so that conventional powdersmay fill the recess or the powder within the recess may be the onlypowder ignitable by percussion, or both may be ignitable by percussion.

Various'types of powders may be used for the various elements. Forexample, pure nitrocellulose powder may be used for the main propellantcharge body and is preferably a porous powder. The porous powder assuresgood burning and ignition due to its large surface area and may becompressed into a firm form-retaining mass at relatively low pressureswithout the pores being closed thereby. The powder foil is preferablypercussion-sensitive, unless it is desired only to have the powderwithin the recess percussion sensitive.

The powder body may have various shapes and forms, and the powder foilmay be of various thicknesses dependent upon the particular requirementsto be met. For example, the thickness of the powder foil and the powdercharge mass will depend upon the percussion or impact energy that isavailable and the desired propellant energy.

As a particular example, the powder body may be ring shaped with thinpowder foils closing both ends of the aperture and have a thickness of0.2 mm. Also, the propellant charge should preferably have anitroglycerin content of at least 40 percent. The amount ofpercussion-sensitive powder to be filled in the recess would be directlycorrelated with the thickness of the foil covering the recess, if thefoil is not percussion sensitive. Thus, in this case, it is particularlydesirable to keep the foil as thin as possible.

Further objects, features and advantages of the present invention willbecome more clear from the following detailed description of a singlepreferred embodiment shown in the attached drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a cross-sectional viewthrough the axis of symmetry of a consumable cartridge constructedaccording to the teachings of the present invention; and

FIG. 2 is a top plan view of the cartridge of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION As shown in FIGS. 1 and 2, thecylindrical propellant powder body or element 1. may be either cast,poured or pressed from a porous powder, preferably in a ring form with acentral aperture extending entirely therethrough. Both axial ends of thecentral aperture are covered by means of percussion-sensitive powderfoils 2. The central recess 3 is partially filled with loose grainpowder 4.

The illustrated cross-sectional dimensions and height of the powder ring1, as well as the thickness of the foil 2 and the quantity of loosepowder 4 have been set forth as specific advantageous structuralelements. According to the broader aspects of the present invention, allof the above characteristics may be widely varied. For example, thesensitivity to ignition of the powder body 1 may be increased by formingthe central recess with a star-shaped cross-sectional profileperpendicular to the axis of symmentry. Also, less simple arrangementsmay be constructed according to the teachings of the present invention.

We claim:

1. A caseless consumable propellant cartridge for commercial andindustrial apparatus not employing a projectile for driving bolts, orthe like, consisting essentially of easily combustible material andcomprising a dimensionally stable propellant powder body having agenerally central recess therein, an ignitor powder ignitable bypercussion and in said recess, said propellant powder body is a flattablet having an axis of symmetry, said recess centrally extends oversubstantially the entire axial height of said tablet, said recess opensin one axial direction from said tablet and including a powder foilattached to said tablet covering said recess, and the walls of saidrecess and the adjacent surface of said powder foil are provided with acoating consisting of a highly percussion-sensitive powder.

2. The device of claim 1, wherein said coating powder is selected fromthe group consisting of tetrazene and tetrazenetnzrnate.

3. A caseless consumable propellant cartridge for commercial andindustrial apparatus not employing a projectile for driving bolts, orthe like, consisting essentially of easily combustible material andcomprising a dimensionally stable propellant powder body having agenerally central recess therein, an ignitor powder ignitable bypercussion and in said recess, said propellant powder body is a flatannular ring having a central through recess, a powder foil coveringeach end of said central recess in said annular ring, said powder foilsare readily ignitable solely by percussion, and said foils are coatedwith a percussion-sensitive powder.

4. The cartridge of claim 3, wherein said percussion-sensitive powder isselected from the group consisting of tetrazene and tetrazene-trizinate.

5. A caseless consumable propellant cartridge for commercial andindustrial apparatus not employing a projectilc for driving bolts, orthe like, consisting essentially of easily combustible material andcomprising a dimensionally stable propellant powder body having agenerally central recess therein, an ignitor powder ignitable bypercussion and in said recess, said propellant powder body is a flatannular ring having a central through recess, a powder foil coveringeach end of said central recess in said annular ring, the walls of saidring recess and the inside surfaces of said powder foils are coated witha percussion-sensitive powder.

6. The cartridge according to claim 5, wherein said percussion-sensitivepowder is selected from the group consisting of tetrazene andtetrazene-trizinate.

7. The cartridge according to claim 6, wherein said powder within saidrecess only partially fills said recess and is in loose granular form.

2. The device of claim 1, wherein said coating powder is selected fromthe group consisting of tetrazene and tetrazene-trizinate.
 3. A caselessconsumable propellant cartridge for commercial and industrial apparatusnot employing a projectile for driving bolts, or the like, consistingessentially of easily combustible material and comprising adimensionally stable propellant powder body having a generally centralrecess therein, an ignitor powder ignitable by percussion and in saidrecess, said propellant powder body is a flat annular ring having acentral through recess, a powder foil covering each end of said centralrecess in said annular ring, said powder foils are readily ignitablesolely by percussion, and said foils are coated with apercussion-sensitive powder.
 4. The cartridge of claim 3, wherein saidpercussion-sensitive powder is selected from the group consisting oftetrazene and tetrazene-trizinate.
 5. A caseless consumable propellantcartridge for commercial and industrial apparatus not employing aprojectile for driving bolts, or the like, consisting essentially ofeasily combustible material and comprising a dimensionally stablepropellant powder body having a generally central recess therein, anignitor powder ignitable by percussion and in said recess, saidpropellant powder body is a flat annular ring having a central throughrecess, a powder foil covering each end of said central recess in saidannular ring, the walls of said ring recess and the inside surfaces ofsaid powder foils are coated with a percussion-sensitive powder.
 6. Thecartridge according to claim 5, wherein said percussion-sensitive powderis selected from the group consisting of tetrazene andtetrazene-trizinate.
 7. The cartridge according to claim 6, wherein saidpowder within said recess only partially fills said recess and is inloose granular form.